Efeito de diferentes doses e métodos na aplicação de enxofre sobre a severidade da ferrugem (Phakopsora pachyrhizi) na cultura da soja

Abstract

Soy (Glycine max) is a species of great economic importance for Brazil and is currently the most cultivated in the world. The nutrients, among them the sulfur, demanded by the culture, can influence the sanity of the plants. In view of the above, the objective was to evaluate the effects of different doses and methods of sulfur application on Asian soybean rust and some yield variables. For that, an experiment was carried out in the field, in the experimental area of the Frontier Sul Federal University, Cerro Largo-RS campus. The products used were a turpentine formulation containing 20% sulfur (Humimax 20S®) and the other 99% elemental sulfur. (0, 80, 120, 160 Kg ha-1), or only in coverage (0, 80, 120, 160 Kg ha-1) as well as in the line and in the cover (40 + 40, 60 + 60, 80 + 80 Kg ha-1). The experimental design was a randomized block design (DBC) and four replications. When the plants reached the R4 stage, the evaluation of the severity of the rust was started, by assigning notes according to the affected leaf area, and the data used to calculate the area below the disease progress curve (AACPD). When they reached maturity for harvest, the plants were removed and evaluated for the weight of one thousand grains (MMG) and yield. It was observed that the sulfur applications influenced the sanity of the plants, producing an increase of more than 150 Kg ha-1, and the on-line application proved to be the most efficient.